1. Simultaneous Equations starter
2x + y = 3 and 3x + y = 5
2x + y = 3
3x + y = 5
The y coefficient of both equations is 1 so eliminate y
subtract
2x – 3x = 3 - 5
-x = -2
x = 2
In both equations the sign of y is the same so subtract
2x + y = 3
2(2) + y = 3 so 4 + y = 3 so
y = 3 - 4
So y = -1
Ans x = 2, y = -1

2. Simultaneous Equations
The coefficients must be equal so
2x + 3y = 7
x – y = 1
Multiply the second equation by 2 to get rid of the x OR
2x + 3y = 7
2x – 2y = 2
Multiply the second equation by 3 to get rid of the y
The coefficients of x are both 2 so get rid of the x.
3y – -2y = 7-2
3y + 2y = 7-2
As the signs in front of x are both the same (+) then subtract
5y = 5
Solve for the remaining letter (in this case y)
y = 1

3. Take one of the original equations
x – y = 1
x – 1 = 1
Replace the letter you have found by its value
x = 2
Ans x = 2 y = 1
Remember when you add or subtract you should only have 1 letter (variable) left